1. Technical Field of the Invention
The invention relates to a liquid drop discharge device that discharges liquid drops to a substrate.
2. Description of the Related Art
A device that pattern-prints a liquid material such as liquid ink to a relevant substrate of glass or paper phenol by discharging the liquid material to the substrate (liquid drop discharge device) has been used in a variety of technical fields. Recently, another use has been suggested to pattern-print the wiring of electrical circuits onto a substrate by discharging a metal-diffused solution to the substrate (for example, refer to Japanese Unexamined Patent Application Publication No. 2002-261048)
In a liquid discharge device, a discharge head for discharging a liquid drop is provided over a substrate to discharge the liquid drop to a target position on the substrate. In this case, the relative position of the discharge head and the substrate can be properly adjusted to discharge the liquid drop for pattern printing.
However, in the case of a conventional liquid drop discharge device, a liquid drop may be solidified and clog a discharge port of a discharge head. Thus, the liquid drop may be discharged in an unexpected direction or along a different course by being bent by the force of air resistance. As a result, the liquid drop lands at a position other than its initial target, thereby causing a false wire pattern of an electric circuit. In addition, the metal-diffused solution should not be wasted in consideration of its generally high price.
There has been a method of shortening the gap between a substrate and a discharge head (platen gap) to avoid the influence of air resistance, but this method cannot be applied to a case that there is unevenness on the shape of the substrate. When the weight of a liquid material (weight of ink) to be used is small, the liquid material may be easily influenced by air resistance. Therefore, it may be difficult to obtain an effect of avoiding the influence of air resistance in spite of a short platen gap.
The present invention has been made in consideration of the above problems. It is therefore an object of the present invention to provide a technique of discharging a liquid drop precisely to a target position of a substrate.